Building block



Dec. 13, 1938. E. R. HA RRAP 1 2 BUILDING BLOCK Filed Feb. 4, 1957 Fig. I.

Patented Dec. 13, 1938 I UNITED STATES FATENT QFFHQE BUILDING BLOCK Eric Russell Harrap, Manchester, England Application February 4, 1937, Serial No. 124,118 In Great Britain February 24, 1936 4 Claims. (01. 72-38) This invention relates to building blocks. An build a wall the blocks .are arranged in the manimportant object of the invention is to provide ner shown in Figure 2 of the accompanying drawa light rigid block having excellent acoustic ing, which is a plan view. It will be seen that the properties, and therefore particularly well adaptsteps i of adjacent blocks overlap and that the 5 ed for the production of partition walls. space between them is filled with mortar 6. It

A further object of the invention is to prowill also be seen that the arrangement both envide a block which will absorb sound to a large sures that the asbestos cement layer is continuextent within itself and also prevent any residual one through the wall and adds rigidity to the wall. sound from passing through to the next room. In the block shown in Figure l the asbestos Other objects of the invention are to manufaccement sheet I is symmetrically arranged within 10 ture such blocks by a very simple process and to the block and thus the transmission of sound is provide improved methods of forming such blocks prevented to the same extent in both directions. into walls. The sound is absorbed to a large extent within In proceeding according to the invention I key the porous cement facings and at the same time a porous mineral facing, which preferably takes any residual sound is prevented by the asbestos 15 the form of porous cement, to an impermeable cement sheet from passing through the wall, or sheet capable of preventing the passage of sound at least is reduced in amount so that such blocks to a substantial extent. The construction of my serve not only to reduce the noise produced in a improved blocks depends largely upon whether room, but also serve to prevent the noise being they are intended primarily for preventing sound transmitted through a partition wall to the next 20 passing through a wall or for acoustic absorption. room, or at least to reduce the amount that is In order that a clearer understanding of the transmitted.

present invention may be had attention is direct- It will be observed that the depth of the porous ed to the accompanying sheet of drawings in cement from the face or back of the block to Which the sheet varies continuously along the block and 25 Fig. 1 is a perspective view of a block resting thus the block can absorb sound to practically on one of its side faces. the same extent whatever the frequency of the Fig. 2 is a horizontal sectional view of a secsound. tion of a wall built of the units shown in Fig. l. The exposed surfaces of the block may be ren- Fig. 3 illustrates in section the manner of atdereol with cement or plaster to provide a smooth 3O taching modified units for greater acoustic abfinish, and the porous cement forms a very good sorption. key for such a finish.

Fig. 4 illustrates a modified manner of secur- When the blocks are intended primarily or to ing the units shown in Fig. 3. a large extent for acoustic absorption they may The blocks for both absorbing and preventbe made and fixed in the way shown in Figure 3. 35 ing the transmission of sound may be rectangular The blocks illustrated consist of asbestos cement overall, but preferably only their faces are recsheets i having porous cement l keyed to one tangular, each end being formed with a projectface only, and the ends of the blocks are not ing step that is less than half the thickness of formed with steps as are the other blocks. The

4 the block so that one face is longer than another. blocks are secured to a support 8 by nails or In building a wall the blocks are arranged so screws, such as the nails shown at 9, through felt that the steps in adjacent blocks overlap and it. Figure 4 of the accompanying drawing shows form spaces in the middle of the wall which are an arrangement in which resilient metal clips I l filled with mortar. One such block is shown by are fixed to the support 8 and engage in the cor- 5 way of example in Figure 1 of the accompanying rugations of the blocks. drawing. It consists of an asbestos cement sheet It will be observed that the blocks shown in l of alternating dove-tail shape symmetrically Figures 3 and 4 are free to move slightly as a arranged between two facings 2 and 3 of porous whole, with the result that the development of cement. These porous cement facings present resonance is prevented or reduced.

rectangular faces, but the 2 is stopped short of It is within the invention to employ, say, a 50 the ends, in the manner shown, so as to form two sinusoidal sheet and to secure the porous cement steps 4 and 5. As an illustration of the size of or the like to it on one or both sides by means such a block, the larger face may be 19 x 9 inches, of keys integral with or fixed to the sheet, but the block may be 4 inches thick and the asbestos it is preferred so to shape the sheet that when cement sheet may be inch thick. In order to porous cement is poured on to it in a liquid con- 55 dition it is automatically keyed to it on setting by virtue of the shape of the sheet, as is the case for example in the blocks illustrated.

A further feature of the invention is concerned with the method of manufacture of such blocks. It is in practice very difficult to cast porous cement to exact dimensions. According to the invention, blocks of porous cement are cast in any shape that is convenient and then are broken up into small pieces which are used as aggregate in the production of the porous material in the blocks described above. Thus this porous material preferably consists of small pieces of porous cement bound together by ordinary cement.

The blocks not only possess good acoustic properties, but are fireproof and unaifected by water, in that they do not warp or sag when wetted. Moreover, the use of a non-porous sheet enables the blocks to carry compression loads far greater than normal porous blocks.

I claim:

1. A wall made from a supporting structure, a plurality of building blocks each consisting of an impermeable sheet capable of preventing the passage of sound to a substantial extent, said sheet having a porous mineral facing keyed to one side, and resilient means interposed between the unfaced sides of said blocks and said structure.

2. A generally rectangular block for wall construction comprising a substantially rigid impermeable sheet of plastic insulating material bent back and forth to provide a plurality of dovetailing loops adapted to extend vertically when the block is positioned, and a porous mineral facing permanently keyed to said dovetailing loops.

3. A generally rectangular block for Wall construction comprising a substantially rigid impermeable sheet of asbestos and cement bent back and forth to provide a plurality of dovetailing loops adapted to extend vertically when the block is positioned, and a porous mineral facing permanently keyed to said dovetailing loops on each side thereof.

4. A generally rectangular block for wall construction having a height greater than its thickness and a length greater than its height comprising a substantially rigid impermeable sheet of asbestos and cement bent back and forth to provide a plurality of dovetailing loops adapted to extend vertically when the block is positioned, and a porous mineral facing permanently keyed to said dovetailing loops on each side thereof. one side of said block being longer than the other and extending beyond each end thereof.

ERIC RUSSELL HARRAR 

